Abstract: The present invention relates to a batch process for washing of soil, sediment, sludge and other Fe containing substrates to remove toxic metalloids, notably As and Sb, and toxic metals, notably Pb, Zn, Cd, Cu, Ni, Hg, Mo, Mn, Tl, Cr, Cs, Sr, Th and U. The present invention aids in treatment of waste washing and rinsing solutions generated from washing the substrate contaminated with toxic metalloids and with toxic metals. The invention furthermore aids in reclamation of washing and rinsing solutions, reagents and other materials, and in activation of recycled chelator for more efficient removal of toxic metals from substrate.

Abstract: A batch process of remediation of soil and sediment contaminated with toxic metals includes the steps of treating contaminated soil and sediment with a solution containing aminopolycarboxylic chelating agent, rinsing the soil/sediment solid phase to remove residues of mobilized toxic metals, treating the used process waters to recycle chelating agent and clean process solutions and placing the remediated soil/sediment on a permeable horizontal reactive barrier to prevent emission of contaminants. In the batch process, toxic metals are removed from process solutions by alkaline adsorption of polysaccharide adsorbents. By applying alkaline adsorption the efficiency of toxic metal removal from process solutions and alkaline and acidic recycling of chelating agent is significantly improved.

Abstract: A batch process of remediation of soil and sediment contaminated with toxic metals includes the steps of treating contaminated soil and sediment with a solution containing aminopolycarboxylic chelating agent, rinsing the soil/sediment solid phase to remove residues of mobilized toxic metals, treating the used process waters to recycle chelating agent and clean process solutions and placing the remediated soil/sediment on a permeable horizontal reactive barrier to prevent emission of contaminants. In the batch process, toxic metals are removed from process solutions by alkaline adsorption of polysaccharide adsorbents. By applying alkaline adsorption the efficiency of toxic metal removal from process solutions and alkaline and acidic recycling of chelating agent is significantly improved.